Lystrosaurus species composition across the Permo-Triassic boundary in the Karoo Basin of South Africa
Lystrosaurus species composition across the Permo-Triassic boundary in the Karoo Basin of South Africa
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DOI：
10.1111/j.1502-3931.2007.00011.x
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发表时间：
2007-06-01
期刊：
影响因子：
1.5
通讯作者：
Smith, Roger M. H.
中科院分区：
文献类型：
--
作者：
Botha, Jennifer;Smith, Roger M. H.
水龙兽是少数在二叠纪末大灭绝中幸存下来的兽脚类之一，也是唯一一个大量存活的兽脚类。这项研究确定了从二叠纪和三叠纪地层中发现的水龙龙物种，以确定南非卡鲁盆地二叠纪-三叠纪（P-T）边界物种组成的变化。从博物馆收藏和最近的野外工作产生的数据被用来对总共189个水龙兽标本进行地层排列，以确定哪些物种在灭绝事件中幸存下来。结果表明，L. curvatus和L.在大灭绝事件之前，马凯吉一起生活在卡鲁洪泛平原上。L.马凯吉没有在南非的三叠纪存活下来。L. curvatus幸存下来，但没有蓬勃发展，很快就灭绝了。本文记述了水龙兽L. murrayi和L. declivis出现在早三叠世。可能是L. murrayi和L. declivis与L. maccaigi和L. curvatus，并有特殊的适应，是有利的早三叠世的环境。我们建议L. Maccaigi的发现可以作为一个生物地层学标志来指示南非最晚的二叠纪地层，并且，为了支持先前的提议，Lystrosaurus不应该被用作三叠纪地层的唯一指示。我们的现场数据还表明，L。curvatus可作为P-T界线段的生物地层标志。
Lystrosaurus is one of the few therapsid genera that survived the end-Permian mass extinction, and the only genus to have done so in abundance. This study identifies which species of Lystrosaurus have been recovered from Permian and Triassic strata to determine changes in the species composition across the Permo-Triassic ( P-T) boundary in the Karoo Basin of South Africa. Data generated from museum collections and recent fieldwork were used to stratigraphically arrange a total of 189 Lystrosaurus specimens to determine which species survived the extinction event. Results reveal that L. curvatus and L. maccaigi lived together on the Karoo floodplains immediately before the extinction event. L. maccaigi did not survive into the Triassic in South Africa. L. curvatus survived, but did not flourish and soon became extinct. Two new species of Lystrosaurus, L. murrayi and L. declivis, appeared in the Early Triassic. It is possible that L. murrayi and L. declivis occupied different niches to L. maccaigi and L. curvatus, and had special adaptations that were advantageous in an Early Triassic environment. We suggest that L. maccaigi may be used as a biostratigraphic marker to indicate latest Permian strata in South Africa and that, in support of previous proposals, the genus Lystrosaurus should not be used as a sole indicator of Triassic-aged strata. Our field data also show that L. curvatus may be regarded as a biostratigraphic indicator of the P-T boundary interval.